Bard macro

[Bardo]

...but if you leave it how you have it now, it'll use heavy shot even if misery's end or bloodletter is available, which is inefficient dps-wise.

I don't think that's correct.
Heavy Shot isn't just 150 potency, you need to remember that it can also proc straighter shot.
You can only proc a "reset" of BL every 3 seconds, so there is virtually no way to miss a BL reset by prioritizing HS and always weaving BL.
However, if you fire BL while the GCD is up, you DO delay your GCD every single time.
And that is nearly always a dps loss.

The only reason you should ever prefer ME over HS when the GCD is up is if you know it's going to be the last shot before something dies.
So in my opinion, if you're going to macro BL/ME together with HS, HS should come first so that you can force your off-globals to weave instead of delaying your GCD.

/micon "Heavy Shot"
/ac "Heavy Shot" <t>
/ac "Misery's End" <t>
/ac "Bloodletter" <t>